CPR: Right Pressure from Rescuers

15. October 2010

Rhythm isn’t everything in cardiopulmonary reanimation. It takes a deep compression of the thorax for the massage to reach the heart. Gadgets simplify the daily work as a rescuer. And there is already an iPhone-version of it which is a bit questionable.

Cardiopulmonary reanimation (CPR) is one of the medical measures rather not that good to train on a severe case. Theoretically most of the physicians and even quite a few amateurs have those couple of recommended first-aid steps in their head what to do in case of cardiac arrest. But once it gets serious, the result often is not optimal. Nerves flutter and quite frequently – due to a lack of training – the feeling for the right balance lacks as well, most of all in thorax compression.

Little brother is coaching you!

And because of that, there are training courses offered with phantom dolls, where the realism depends on the price of the doll and thus most of the time on the price of the course. In times of mobile terminal another trend has developed as well which – at least in Northern America – keeps the regulatory authorities busy: There are more and more mobile solutions suggesting that they support the first aid helper be it a physician or not in a potentials reanimation situation. The less spectacular representatives of this species are software solutions for the cell phone. They reproduce – more or less good – the recommendations of the American Heart Association (AHA) regarding cardiopulmonary non-professional reanimation. Imagine it as kind of a mini-slideshow you can put next to you during an emergency situation in order to go by the instructions step by step. Better solutions provide an acoustical instruction what to do: They “tell” the life saver what he has to do and when. Another multimedia element often is something like a metronome giving the rescuer the “100 per minute” rhythm for a cardiac massage. One example for such a rather sophisticated system is the PocketCPR the size of a hand. Zoll Medical distributes it, a US company manufacturing defibrillators among other things. It was even approved by the US regulatory authorities FDA as a freely available tool for medical emergencies.

Press until the sensor squeaks

A wrong compression frequency is one of the most frequent mistakes inexperienced life savers make during CPR, mainly when the power decreases, the compression frequency drops as well. But right frequency is not everything. The depth of the compression is essential as well: The rescuer has to add some pressure in order to achieve pumping those 30 percent of the normal blood volume through the body required for a properly executed CPR in accordance with scientific tests.

But how can you make sure that the first responder really presses strongly enough? Zoll Medical has found the answer to that: The company equipped its PocketCPR-system with an acceleration sensor developed by the IT company Analog Devices. If you put the device on the thorax during reanimation and thus “co-reanimate” it, the sensor generates the depth of the compression taking into consideration acceleration and compression frequency by using an algorithm. A similar technology is being applied in some adult defibrillators made by the same manufacturer. So now we have the miniaturized and electrode-free version. According to the manufacturer the device is calibrated for people starting the age of eight. It securely can register the compression depth recommended by the AHA of 1.5 to 2 inch (3.8 to 5.1cm). Mark Totman, president of the Zoll Medical subsidiary Bio-Detek responsible for the PocketCPR-sytem, is convinced that the quality of reanimation is improved by the digital companion: “Many people don’t want to reanimate because they feel that they are not trained well enough. Our device can give them the necessary self-confidence to act in an emergency.”

The iPhone-Version gets lousy ratings

The PocketCPR-system with its sophisticated acceleration sensors – here a highly dramatic product video – is available at 120 UD-Dollars. Owners of an iPhone can save this money because in Germany Zoll Medical offers an iPhone-application for only 2.99 USD which can assist during CPR in an emergency situation. This app available since 2009 uses the acceleration sensor integrated in the iPhone to evaluate the compression depth. But it’s not that simple to place the iPhone on the thorax in an emergency situation and compress powerful at the same time. It’s too smooth, too flat and is made of too much glass.

It’s attached to the wrist instead. And it is not approved by the FDA. Rather a gimmick than real help then? The users at least react critical: Of 28 ratings for this app made in Apple’s AppStore just mediocre 2.5 of five possible stars. Just for fairness’ sake we have to say that the iPhone version of PocketCPR is not being advertised as a reanimation aid but as a tool for training. On your pillows – get set – and go!